Table 2.

Examples of incorporation of cells into injectable scaffolds for cartilage regeneration

	Cell source	Major materials	Advantages
Chondrocytes (fully differentiated cells)	Chondrocytes	CS	Prolonged cell survival, retained cell morphology and improved chondrogenesis when cultured in vitro [137]
	Chondrocytes	CS and type II collagen	Improved cellular condensation and chondrogenesis of embedded chondrocytes to promote cartilage regeneration [136]
	Chondrocytes	Oligo(lactic acid)-b-PEG- b-oligo(lactic acid) (PEG-LA)	Improved formation of cartilage matrix of aggrecan and collagen type II/VI [138]
Stem cells	ESCs	PEG	Promoted ESC differentiation into chondrogenic cells and formation of neocartilage ECM [141]
	MCS	Agarose, hyaluronan acid, PEG or alginate	Increased chondrogenic differentiation of the cells for the cartilage reconstruction [50, 144–146]
	iPSCs	Polylactic	Prompted cartilage regeneration of an osteochondral defect [150]
	PBMCs	Graphene oxide (GO)-polyethylenimine (PEI)	Easily obtained from peripheral blood and have a similar potential of chondrogenic differentiation and cartilage generation compared with MSCs [151]